Mechanism of inhibiting a disintegrin and metalloprotease 8 expression on inflammatory damage in alcoholic liver fibrosis mice
Objective To explore the mechanism of inhibiting a disintegrin and metalloprotease 8(ADAM8)expression on inflammatory damage in alcoholic liver fibrosis mice.Methods C57BL/6N male mice were randomly divided into the control group,the alcohol group,and the plasmid group,with 10 mice in each group.The alcohol group and plasmid group were fed alcohol liquid feed on a daily basis and gavaged with 31.5%ethanol(5 g/kg,twice a week);The control group was fed control liquid feed and gavaged with an equal amount of saline.The plasmid group was injected with the effective plasmid ADAM8-small guide RNA3(sgRNA3)(2 g/kg,twice a week)to inhibit the ADAM8 gene through the tail vein,while the alcohol group was injected with an equal amount of saline through the tail vein for 8 weeks to induce alcoholic liver fibrosis.After eyeball blood collection,the mice were euthanized,and their liver was separated and extracted.Sirius red and HE staining were employed to assess liver fibrosis and damage;Western blotting was used to determine the expression of α-smooth muscle actin(α-SMA),collagen Ⅰ,and ADAM8;Real-time PCR was used to measure the expression of ADAM8 mRNA;the expression of ADAM8,transforming growth factor-β1(TGF-β1),p-p38 MAPK and heat shock protein 27(HSP27)proteins was detected by Western blotting,Biochemical detection were used to detect alanine aminotransferase(ALT)and aspartate transaminase(AST)activity;tumor necrosis factor-α(TNF-α)and interleukin-1(IL-1)levels were determined by ELISA.Results The alcohol group had increased collagen fiber volume fraction,liver injury scores,and positive area rates of α-SMA and collagen Ⅰ;the expression of ADAM8 mRNA and ADAM8 protein increased,with increased positive area rate;and levels of AST,ALT,TNF-α,and IL-1 were higher,along with increased expression of TGF-β1,p-p38MAPK,and HSP27 proteins.In the plasmid group,the collagen fiber volume fraction,liver injury scores,and positive area rates of α-SMA and collagen Ⅰ was reduced;the expression of ADAM8 mRNA and protein was reduced,with decreased positive area rate,and levels of AST,ALT,TNF-α,and IL-1 were lower,along with reduced expression of TGF-β1,p-p38MAPK,and HSP27 proteins.Conclusion Downregulation of ADAM8 expression can alleviate inflammatory damage by inhibiting TGF-β1/p38MAPK signaling pathway to improve alcoholic liver fibrosis in mice.
A disintegrin and metalloprotease 8Alcoholic liver fibrosisInflammationDamageTransforming growth factor-β1/p38 mitogenactivated protein kinase signaling pathwayWestern blottingMouse